Table of Content

    25 June 2015, Volume 54 Issue 3
    Analytical Calculation of Wave-Induced Seepage Forces on the Porous Compound Vertical Circular Cylinder
    CHEN Ruizhi;HUANG Hua;ZHAN Jiemin;ZHU Menghua;GUO Zongxiao
    2015, 54(3):  1-9. 
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    Based on Biot seepage consolidation theory and wave diffraction theory, the analytical solutions to the diffracted water wave potentials and the waveinduced seepage pressures referring to porous compound vertical circular cylinder resting on permeable elastic seabed are derived by applying the eigenfunction expansion approach, and then the wave-induced lift force and overturn moment caused by the seepage pressure on the bottom of compound vertical circular cylinder are accordingly evaluated and are compared with direct diffracted wave force and moment. The results demonstrate that the porosity of the lateral surface of the circular column resting on a circular base will lead an obvious reduction in direct horizontal wave loads on compound cylinder and certain reduction in seepage overturn moment on the bottom of compound cylinder, and having slight influence on direct vertical wave loads and waveinduced seepage uplift force on compound cylinder .The variation of ocean condition and structure geometry condition may have some influence on waveinduced seepage loads, especially on seepage moment. In certain condition, wave-induced seepage loads may have same order of magnitude as the direct wave loads.
    Identification of Distributed Damage in Bridges from Vehicle Induced Dynamic Responses
    LI Hailong,LU Zhongrong,LIU Jike
    2015, 54(3):  10-13. 
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    A distributed damage identification approach under moving vehicle loads is presented based on dynamic response sensitivity. Numerical studies are carried out on a simply supported beam under a vehicle with nonlinear springs for identication of distributed damage due to the crack. Combined Newmark direct integration method and Runge-kutta method are used to calculate the dynamic responses of the coupled bridge-vehicle system. The numerical results show that the distributed damage(s) can be identified accurately even with 5% noise in the measured acceleration data. And more accelerometers are needed if there are multiple cracks in the bridge.
    Physical Design Method of Multi-Mode and Multi-Clock Domain Chips
    QIN Xiaoying;ZHENG Xiangnan;WANG Zhengji;SU Tao
    2015, 54(3):  14-18. 
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    To reduce the cost and difficulty of chip testing, also improve quality and yield, memory build-in self-test (MBIST) mode and scan chain test mode are included in mass-production chips. As more functions are integrated on a single chip, multiple different clocks are adopted in design. The solution presented  is a physical design method named Mix-mode, which realize normalization of multi-mode based on changing the timing constraints. The method was applied in design of a video processing chip based on 130 nm process and IC Compiler (ICC)  used for placement and routing. The results showed that  the physical layout was better in terms of runtime, timing, power consumption, area and total wire length than that obtained from the Multi-mode method provided by ICC.
    Optimization of Transfer Waiting Time of Guangzhou Waterbus
    LI Jun,;HUANG Sha
    2015, 54(3):  19-25. 
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    A method to optimize the transfer waiting time of the waterbuses is presented. The operation time and frequencies of waterbuses are assumed to be fixed, a mathematical program model is built to coordinate the arrival times of different waterbus lines at the given wharf so that the total waiting time is minimized. The genetic algorithm is proposed to solve the model. The Xidi Wharf of Guangzhou Waterbus is chosen to test the model. The result indicates that the total transfer waiting time is significantly reduced. The proposed genetic algorithm is a fast and efficient method to solve the model with acceptable error.
    Research on Online Self-Organizational Learning GD-FNN Algorithm by Grading
    ZUO Jun;ZHOU Ling;SUN Yamin
    2015, 54(3):  26-29. 
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    General dynamic fuzzy neural network (GD-FNN) algorithm is proposed based on the elliptic basis function (EBF). Fuzzy rules generated from the algorithm are intelligibility. It can be used as a modeling tool. and a tool of knowledge extraction. Because of a novel on-line parameter allocation mechanism for allevialing the random selection in initialization without relation to different input variable range, the proposed GD-FNN based on fuzzy ε-completeness is more easy to construct a good fuzzy system in performance.The simulation program is also developed based on the GD-FNN algorithm and ideal results are achieved by simulation in specific design case.
    Experimental Study on Out-of-Plane Dynamic Stability  of Circular Shallow Arch
    LI Kangjie;LIU Airong;LU Hanwen;YU Qicai
    2015, 54(3):  30-35. 
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    The periodic load on the arch, in general, only causes the symmetric in-plane vibration of the arch. However, under certain conditions, it can cause in-plane anti-symmetric vibration and out-of-plane symmetric vibration with large amplitude, which is so-called the instability problem of an arch structure due to the parametric resonance. Aimed at studying the out-of-plane dynamic stability problem of circular shallow arch, the experimental work is conducted trying to explore mechanism of the out-of-plane dynamic instability under concentrated periodic load. By applying APS series vibrator, the single point harmonic excitation at vault was simulated. The B&K modal testing system was used to gain the transverse vibration response of circular arch including its vibration mode shape and damping ratio. The boundaries of unstable domain were distinguished by way of constant frequency back-and-forth sweep. The experimental results were compared with those from theory analysis, and the results show that remarkable transverse parameter resonance of the structure appears when the frequency of external excitation is about twice of the structural frequencies.  The parameter resonance occurs only when the external excitation amplitude is greater than the critical excitation force.Tthe existence of the damping affects the value of the critical excitation force. The greater is the excitation, the easier does the parameter resonance phenomenon occur. The experimental work reported  verifies the accuracy of calculating the outofplane dynamic instability domain of the circular shallow arch, and presents that research has reference value for the design of dynamic stability of arch structure.
    Existence and Uniqueness of Global Solution for a Model of Immune Cells Inhibiting Tumor Immune Evasion
    CONG Baili;FENG Zhaoyong;WEI Xuemei
    2015, 54(3):  36-43. 
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    A mathematical model of immune cells inhibiting tumor immune evasion is studied. The model involves strongly coupled parabolic PDEs. Applying the Lptheory, Schauder-estimate and Banach Fixed Point Theorem, it is proven that the problem has an unique local solution. Then by extension method, that the local solution is global is proven.
    Robust Adaptive Boundary Control of a Flexible Manipulator with Unknown Boundary Disturbance
    WENG Xuan;YANG Longgang;LIU Yu;ZHAO Zhijia;WU Yilin
    2015, 54(3):  44-50. 
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    To suppress the vibration and improve the vibration control for a flexible manipulator with the system parametric uncertainty and unknown boundary disturbance uncertainty, a robust adaptive boundary control with boundary disturbance observer is proposed by using adaptive control and boundary control technologies based on the manipulator's parameter estimation to suppress the vibration of the manipulator. With the proposed control scheme, system parameter uncertainty can be compensated and the control spillover problem can be avoided, and the boundary disturbance observer can attenuate and track the unknown boundary disturbance. The stability and uniform boundedness of the control system are both proved by Lyapunov's synthesis method. Simulation results demonstrate the effectiveness of the proposed control method to suppress the manipulator's vibration.
    Analysis of a Delayed SEIR Epidemic Model with Saturation Incidence
    YANG Junxian,YAN Ping
    2015, 54(3):  51-55. 
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    A delayed SEIR epidemic model with saturation incidence rate is proposed and analyzed, and the basic reproductive number R0 is defined. By analyzing the corresponding characteristic equations, the local stability of a diseasefree equilibrium P0 and an endemic equilibrium P* are discussed. Further, by the comparison principle and constructing Lyapunov functions, it is found that if R0<1, the disease free equilibrium P0  is globally asymptotically stable, and if R0>1, the endemic equilibrium P*is permanent.
    Difference Operators of Meromorphic Functions and Shared Values
    ZENG Cuiping
    2015, 54(3):  56-59. 
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    The problems of uniqueness concerning difference operators are studied. And some results on two general difference operators of meromorphic functions shared a value are obtained.
    Euler-Maruyama Numerical Solutions of Highly Sensitive Mean-Reverting Stochastic Differential Equations with Markovian Switching and Applications in Finance
    ZOU Li;YIN Juliang
    2015, 54(3):  60-67. 
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    A highly sensitive mean-reverting stochastic differential equation is a kind of widely used financial model. A Markovian switching mechanism is added into this model, and resulting in general financial model (RS CKLS for short). The purpose is to study the Euler numerical solution of RS CKLS and apply RS CKLS to study financial issues. Firstly, it is proved that there exists a unique positive global solution for a RS CKLS under appropriate conditions. Then it is shown that the Euler numerical solution of a RS CKLS converges to its real solution in the sense of probability. Finally a RS CKLS is applied to conduct empirical analysis of 7-day Shanghai interbank offered rates. Maximum likelihood method is used to estimate model parameters, and hypothesis test results show that the RS CKLS has a better performance in fitting 7-day Shanghai interbank offered rates compared with a CKLS.
    Traveling Wave Solutions of a Competition Diffusion System with Nonlocal Delays
    WU Fuzhen
    2015, 54(3):  68-73. 
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    The traveling wave solutions of a competitive system with nonlocal delay are concerned. By combining fixed point theorem with generalized upper and lower solutions, the existence of traveling wave solutions is established. Then the asymptotic behavior of traveling wave solutions is obtained by the idea of contracting rectangles. Finally, the nonexistence of traveling wave solutions is proved by the theory of asymptotic spreading.
    Qualitative and Quantitative Determination of 17 Gases from SF6 Electrical Equipments by Dual-Channel Gas Chromatography-Pulsed Discharge Helium Ionization Detector
    ZHOU Yongyan;XIE Di;TANG Nian;LUAN Tiangang;LI Li;WANG Xiaowei
    2015, 54(3):  74-79. 
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    The qualitative and quantitative determination of gases released from SF6 electrical equipments plays an important role in diagnosing the failure of SF6 electric equipments. In this work, 17 gases were determined based on a dualchannel gas chromatography (GC) equipped with a helium ionization detector in GIS (Gas Insulated Switchgear), including CO, CF4, CH4, CO2, C2F6, C2H2, COS, C2H4, C2H8, H2S, SO2F2, C3F8, C3H6, C3H8, CS2, SO2 and S2OF10. Gases were transported into channel A and channel B of the instrument. Channel A was composed of a 05 nm column and a Poropak Q column while channel B was made up of HP-5 capillary chromatographic column. As a result, target compounds could be separated completely. Moreover, the limit of detection (LOD) of these gases was approximate 10-8 and the relative standard deviation (RSD) was less than 7%. Therefore, the proposed method was sensitive, precise and was finally applied to determine 15 gases in real samples from GIS. SO2 and SO2F2 could be detected in the GIS, which indicated the spark discharge inside the equipment.
    Research on Cyclo-Dipeptides from the Coral-Derived Endophytic Bacteria Pelomonas puraquae sp.nov of South China Sea
    DENG Yun;HU Guping;CHEN Xiaojie;LIU Bingxin;DAI Shuwen;HE Xixin;ZHANG Cuixian
    2015, 54(3):  80-84. 
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    Eight compounds 1-8 were obtained from the fermentation broth and mycelium of B-2 through modern methods for isolation and purification in order to research secondary metabolites from coral-derived endophytic bacteria Pelomonas puraquae sp. nov(B-2) . Their structures were analyzed by 1H and 13-C NMR, MS and physical methods. The results indicated that they were composed of 8 compounds including cyclo(Hyp-Phe)(1), cyclo(Pro-Tyr)(2), cyclo(Phe-Gly)(3), cyclo(Phe-Ala)(4), cyclo(Ala-Tyr)(5), cyclo(Leu-Gly)(6), cyclo(Gly-Val)(7) and cyclo(Ala-Val)(8). They were all cyclodipeptides and first acquired from the coralderived endophytic bacteria Pelomonas puraquae sp. nov(B-2).
    Chiral Transition Mechanism of α-Alanine Confined in the Armchair SWBNNT (9, 9) /Water Complex Environment
    MEI Zemin;TONG Hua;XIA Lili;LU Yang;YANG Xiaocui;WANG Zuocheng
    2015, 54(3):  85-92. 
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    The chiral transition mechanism of α-alanine confined in the armchair SWBNNT (9,9)/water complex environment was studied using the method of quantum chemistry (ONIOM(B3LYP/6-311++G(3df,3pd):UFF)∥ ONIOM(B3LYP/6-31+G(d,p):UFF)) in the paper. The result indicated that, compared s-type α-Ala and intermediate INT1 in the SWBNNT(9,9)/water complex environment with monomer molecules, the bond lengths between oxygen and hydrogen, as well as carbon and hydrogen involving hydrogen transfer were all slightly increased. However, the distance between oxygen and hydrogen was significantly shorten under the same condition. It was found that there were four reaction paths in SWBNNT(9,9). Furthermore, the processes of hydrogen transfer were all realized by the way which made one or two water molecules as bridge. The maximum energy barriers of every path were always coming from transition state where hydrogen transferred from chiral carbon to carbonyl through measurement of the potential energy surfaces of chiral reaction. The minimum of maximum energy barriers was 153.8 kJ·mol-1 in the process that Amino heterogeneous firstly, then successively hydrogen transferred inside the carboxyl and hydrogen transferred from chiral carbon to carbonyl oxygen through two water molecules as bridge. Corresponding to chiral transition of α-Ala in SWBNNT(9,9) only, the minimum of maximum energy barriers was 302.7 kJ·mol-1 which obviously reduced. Moreover, corresponding to chiral transition of αAla in water environment only, the minimum of maximum energy barriers was 167.8 kJ·mol-1 that also reduced. The results showed that the SWBNNT(9,9)/water complex environment provided a preferable catalytic action for chiral transition of α-Ala.
    Synthesis and Growth Mechanism of Zn2SO4(OH)2·2H2O and ZnO Whiskers
    WU Jiansong;LIANG Haiqun;DENG Guoli;YU Zijun
    2015, 54(3):  93-97. 
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    Using Zn2SO4·7H2O, NaOH as raw material, high-quality Zn2SO4(OH)2·2H2O and ZnO whisker was synthesized via liquid precipitation reaction and sintering methods process. The phase,granularity, structure of crystal morphology of whiskers samples were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM) and thermal analysis (TGDTA). The SEM result revealed that :①  the whiskers formed with fine dispersive capability, ② the crystal formed with good whisker quality, ③ the surface was smooth, and ④ the particle was dispersed in uniform distribution. From the point of growth units, the growth mechanism of Zn2SO4(OH)2·2H2O whisker was investigated in this work. The growth unit of Zn2SO4(OH)2·2H2O whisker is[Zn-(OH)64-. The growth process of whisker was determined to be [Zn-(OH)64-and HSO-4 piles up towards onedimensional direction and eventually forms whiskers. After thermal decomposition, the morphology was the same, and Zn2SO4(OH)2·2H2O whiskers eventually became the ZnO whiskers.
    Effect of Hydroxyapatite and Dentifrice Containing Hydroxyapatite on Aqueous Cadmium Adsorption
    LIU Chengxia;SHEN Xiaoqing;YANG Jianzhen;XU Pingping
    2015, 54(3):  98-101. 
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    The effect of hydroxyapatite (HA) particles with various grain sizes and dentifrice containing hydroxyapatite on aqueous cadmium adsorption was studied. Three kinds of suspensions were prepared by adding dentifrice to HA suspensions containing 3% HA with grain sizes of 20 nm, 60 nm and 12 μm with different concentrations. Cadmium ion solutions with initial concentration of 0.2 mg/L were mixed with HA suspensions and dentifrice suspensions respectively, and then were kept still for 24 h. The residual cadmium ion concentration of the supernatant was measured by inductively coupled plasma emission spectrometer, and the sorption rate of cadmium ion was calculated. The sorption rates of cadmium ion of HA particle with 3 grain sizes were above 70%, and 20 nm HA was the best.The sorption rates of cadmium ion of dentifrice containing HA were over 50% by average, and dentifrice containing 20nm HA was the highest. Pure HA and dentifrice containing HA could absorb cadmium ions. HA with size of 20 nm showed the best sorption property. The sorption property decreased by adding dentifrice.
    Potential of Plant-Derived Lead-Binding Proteins in Phytoremediation
    WANG Fengzhu;CHEN Qinfang;YU Lujun;SHU Wensheng;XIAO Shi
    2015, 54(3):  102-106. 
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    Phytoremediation uses plants to remove pollutants including heavy metals from the environment. The roots of the plant channel pollutants residing in soil or water in the environment to above-ground plant tissues for storage. Eventually, these pollutant-containing plant parts can be harvested and properly disposed. Plants thrive by photosynthesis making solar-driven in situ localized phytoremediation a very cost-effective and environmentally-friendly method to rid contaminants. Heavy metals are the undesirable products from industries such as mining and manufacturing and they are toxic to both man and animals. It has been reported that transgenic plants can be used to detoxify heavy metals like mercury, cadmium, arsenate, and selenate from the soil. However, few leadbinding proteins have been isolated from plants. Acyl-CoA-binding proteins (ACBPs) have been demonstrated to bind lead in vitro and in vivo and the potential in using ACBPs for the phytoremediation of lead in transformed plants will be discussed.
    Vitro Properties Invesigation of Histidylated PEG-b-PLG-g-PEIs As Gene Carrie
    BAI Feng;TIAN Shouqing;FENG Ming
    2015, 54(3):  107-114. 
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    The study mainly focuses on cell transfection efficiency and cytotoxicity of a histidylated cationic copolymer in order to explore its potential as a gene carrier. A novel histidylated cationic copolymer,PEG-b-PLG-g-PEIs-HISs(GGIS),was synthesized by free radical polymerization.The chemistry structure of GGIS was confirmed by  1H-NMR.Agarose gelelectrophoresis was performed to study the capacity of plasmid DNA condensation. Particle size and zeta potential were measured at various N/P ratios. Cytotoxicity of GGIS was determined by MTT assay in HEK 293T, Hela, BEL7402 and A549 cells lines .The transfection efficiency of GGIS was specifically evaluated and monitored by flow cytometry. When the N/P less than of 30. The size of the DNA/GGIS was approximately 100~200 nm and the zeta-potential was 10~30 mV.The MTT assay showed that the cytotoxicity of GGIS was obviously lower than PEI 25K. GGIS demonstrated significantly higher transfection efficiency than PEI 25K.Therefore,GGIS with high transfection efficiency and low cytotoxicity has great potential to be used as non-viral gene carriers.
    Consistency Evaluation of Two Clindamycin Palmitate Hydrochloride Preparations
    HUANG Xin;ZHANG Chao;LIN Feng;ZHOU Cuilan;SU Weiwei;PENG Wei
    2015, 54(3):  115-118. 
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    Consistency evaluation was processed between domestic clindamycin palmitate hydrochloride dispersible tables and the original oral solution. HPLC method was applied to detect related substances with acetate (A) and 5 mmol/L ammonium acetatesolutionacetonitrile (50:50) (B) as mobile phase eluting in gradient. Dissolution was conducted by stirring paddle method with w=0.4% SDS as dissolution medium, at the rotate speed of 75 r/min for quality comparison between two products.
    The results showed that the kinds and total contents of related substances in clindamycin palmitate hydrochloride dispersible tablets were lower than that of the original oral solution products and the dissolution rates of both products reached more than 94% in 20 minutes.
    Effect of Homogenization Speed on Morphology and Release of Protein Loaded PLGA Microspheres Made by WOW Method
    HUANG Xiaozhou;CHENG Xiaolan;LUO Yuyan;GUO Zhefei;ZHONG Chen;ZHANG Yongming
    2015, 54(3):  119-124. 
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    Poly (lactic-co-glycolic acid) (PLGA) microspheres loaded bovine serum albumin were prepared by WOW double emulsion method. The influence of homogenization speed during primary emulsion(5 000, 10 000, 15 000 r/min) on the physicochemical properties was investigated. Encapsulation efficiency, drug loading and particle size were used to evaluate the physicochemical properties of the microspheres. The surface and internal morphology of the microspheres was investigated by scanning electron microscopy (SEM). The structure parameters were analyzed by image analysis software. Confocal laser scanning microscopy was utilized to observe protein distribution within the skeletons of the microspheres. Finally, the connectivity of the microspheres was examined by the uptake experiments. Moreover, the release behaviors and the surface and internal structural evolution were also systematically studied. When the homogenization speed increased, the number of surface and internal pores increased, pore size of internal pores decreased. Besides, higher homogenization speed may result in slower drug release and degradation of the microspheres. But it caused no significant difference in the particle size and cross-sectioned porosity. In 10 000 r/min group, the microspheres showed highest encapsulation efficiency and lowest burst release rate in the first day and lowest surface pore connectivity. While in 5 000 r/min and 15 000 r/min group, microspheres released faster, with a higher burst release. The microspheres prepared at different homogenization speed showed different surface and internal morphology, which play a significant role in 〖WTBX〗in vitro〖WTBZ〗 release behaviors.
    Content Variation of Changbai Mountain Allium victorialis L. Functional Components in Different Picking Time and Study on the Lipid-Decreasing Effect
    LI Qianzhu;ZHAO Yujuan;LIU Qiao;DONG Ran;SHEN Minghao
    2015, 54(3):  125-129. 
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    Wild Allium victorialis L. in Changbai mountain was collected as raw materials to study its content variation of functional components in bulbs and leaves with different picking time, and find out the best lipid-decreasing time of Allium victorialis L. boiling liquid. Ultrasonic assisted extraction of flavones, saponins and polysaccharides in Allium victorialis L. and measured contents of the three substances individually, the bulbs and leaves boiling liquid in different picking time was taken and used for the experimental mice induced by high-fat diet. In late July, the bulbs and leaves boiling liquid has obviously decreased the content of triglyceride, total cholesterol and low density lipoprotein cholesterin. However, the liquid has obviously rise the high-density lipoprotein cholesterol. And in bulbs of this picking time: the content of flavones is 4.85 mg/g, the content of saponins is 9.54 mg/g, the content of polysaccharides is 56.91 mg/g. In leaves of this picking time: the content of flavones is 9.77 mg/g, the content of saponins is 10.94 mg/g, the content of polysaccharides is 34.24 mg/g. Wild Allium victorialis L. has a good effect of lipid-decreasing.
    Propagation of the Quasi-Biweekly Oscillations Related to Rainfall Abnormity in the First Rainy Season over Southern China
    CHEN Si;JIAN Maoqiu
    2015, 54(3):  130-137. 
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    The relationship between the quasi-biweekly oscillation(QBW: here defined as a 10~25 day oscillation) abnormity of May-June rainfall over southern China and the QBW propagation from the tropics and mid-latitudes is studied based on the composite analysis. The results indicate distinct QBW propagations in different May-June rainfall abnormal cases. The strong QBW rainfall abnormal cases in May in southern China are linked to the QBW propagations not only from the Bay of Bengal but also from the mid-latitudes of northwestern China. However, the weak QBW rainfall abnormal cases in May are just linked to the QBW propagations from the tropics. In June, the strong and weak QBW rainfall abnormal cases in southern China are influenced by the QBW propagations from the Bay of Bengal and from the mid-latitudes,respectively.
    A Study on Remote-Sensing Inversion of Aerosol Particle Size Distributions over Yongxing Island
    HUANG Anfeng, DENG Ruru, QIN Yan, CHEN Qidong, LIANG Yeheng
    2015, 54(3):  138-144. 
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    Ground-based remote sensing can directly get the radiation characteristics of atmospheric aerosol, which can be used in the study of aerosol particle size distribution. Atmospheric monitoring experiment was carried out on the roof of Marine Station by using ASD spectrometer and the solar radiation was measured. Based on obtained data, this paper applies Monte Carlo to randomly generate the proportions of four aerosol components which are used to approximately solve the extinction equation to retrieve aerosol particle size distribution. The result shows that during the period of experiment the aerosol type of Yongxing Island is similar to the marine aerosol defined by the standard radiative atmosphere; the volume size distribution is bimodal distribution with the peaks at 0.01~0.1 and 1~10 μm respectively; the number concentration distribution is unimodal distribution with the peak at 0.001~0.01μm; the change rule of aerosol number concentration and volume concentration is relevant to both the movement of sea water and the deposition of aerosol particle; the correlation coefficients for number concentration and turbidity index, volume concentration and turbidity index are above 98%, which means that number and  volume concentrations can be used to represent the atmospheric turbidity.
    Multi-Fractal Method's Application Based on Principal Component in Lithology Recognition
    ZHANG Yan; ZHOU Yongzhang; ZHU Jitian
    2015, 54(3):  145-150. 
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    In order to solve the problem that logging curve identifying complex reservoir lithology has multiplicity and uncertainty, this paper uses logs to build principal component variables and takes the principal components with the cumulative variance greater than 85% as input information, ensuring that input variables are minimum and information loss is minimal. and then simplifies the data structure to identify lithology. Based on measured values of gamma ray (GR), deep resistivity (RES_BD), resistivity (RES_BM), shallow resistivity (RES_BS), neutron porosity (TNPH), bulk density (RHOB) and interval transit time (DTCO) in deep-water reservoir of the Qiongdongnan Basin, seven integrated variables were constructed. Principal component 1 and principal component 2, with the total explained variance of 85.11%, can effectively explain the comprehensive information of seven variables. Based on lithologic data obtained from sidewall core, siltstone, mudstone,and fine sandstone can be identified on the cross plot of principal component 1 and principal component 2. Additionally, the multi-fractal method was used to analyze the spectral function curves. The sandstone corresponds to spectral function curve leaning right and mudstone corresponds to spectral function curves leaning left, which can be used as valid evidence to distinguish sandstone and mudstone.
    Study on Ecological-Level of the Poyang Lake Based on Variable Bandwidth Kernel Density Estimation
    LIU Jianyu;ZHANG Qiang; GU Xihui;XIAO Mingzhong;CI Hui
    2015, 54(3):  151-157. 
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    Hydrological processes of the Poyang Lake are significantly altered under the influences of human activities and climate changes. Ecological system has aological alterations indapted to the hydrological conditions before hydrological alterations in the Poyang Lake. Given this, we use various kinds of alterations diagnosis methods to test the lake water level. Then we use variable bandwidth kernel density estimation to fit respectively daily water level for each month before hydrological variations. We regard largest probability of water level as the ecological-level the Poyang Lake. The following results were obtained: ① The variation of water level in the Poyang Lake  occured  in 1979,  with the increase of 0.5 meter in the mean water level. ② Variable bandwidth kernel density estimation is the best statistical method for studying of maximize density water level before hydrological alterations in the  Poyang Lake. ③ After  the hydrological variation, the fill rate of ecological-level reduced significantly. with an  average value of ecological-level fill rate less than 50%. Runoff changes are the major factors influencing the ecological-level fill rate; Water conservancy projects and forest coverage can help to improve the low-flow, so the ecological-level fill would increased significantly in dry seasons after alterations. This research results will provide important scientific basis for the ecological conservation, water ecology and water management within in the Poyang Lake basin in a changing environment.
    Effect of Different Land Surface Schemes on Simulation of Characteristics of Spring Clear Day Boundary Layer in Pearl River Delta Region
    ZOU Zhencao;DENG Yuanchang;DENG Zhiping
    2015, 54(3):  158-164. 
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    By using five different kinds of land surface parameterization schemes (SLAB, Noah, RUC, PleimXiu and SSiB) in WRF model and combining with the latest land cover data Globcover2009, the tests about boundary layer structural features were simulated in the Pearl River delta region from 28 to 29 April 2014. Meteorological parameters, including weed speed at 10m, temperature at 2 m, vertical profile of wind speed and temperature, were evaluated and compared to the observations from 18 surface weather stations and 1 sounding station in the research area. The results show that: ①compared with the USGS land use data, distribution of land use classes in Globcover2009 is more consistent with the current actual type of surface. The simulation precision of wind speed and temperature near the surface can be effectively improved by updating the land use data; ②WRF model can simulate the diurnal variations of surface meteorological parameters basically. Due to the lowly coastal terrain, the simulations of wind speed at 10m are more easily overestimated from these five schemes, while the results of temperature at 2m are underestimated to various degrees. Among them, the simulation result of wind speed in SLAB scheme is the best and the simulated temperature in Noah scheme is more accurate than others, the error between simulations and observations in SSiB scheme is the biggest. ③The vertical profiles of wind speed and temperature obtained by Noah, SLAB, RUC and PleimXiu are almost the same in variation trend and these simulations are in line with the actual situation. The characteristics of atmospheric boundary layer from SSiB scheme are not obvious for the reason that vertical stratification near the ground is set too sparsely.